The ARES-1 Emergency Escape System (EES) is a roller coaster like system for evacuating astronauts or other personnel working on the launch pad in the event of an emergency.
The space shuttle has a similar system, albeit nothing more than a basket that flies away from the pad on a guy wire carrying astronauts to safety. This time around, the minions quickly decided to go to something a little more sturdy and a little less nerve racking (considering it will be used in the ultimate nerve racking situation to begin with), or so they thought. Just as they rushed ESAS, this rushed design turned out to be faulty as well.
It turns out, the new system had to be redesigned to reduce the g-forces on personnel escaping the pad. It seems that the Emperor's comically ineffectual ACME ride designers weren't able to come up with a system that satisfied the astronauts. Lacking the competence to do so themselves, the minions turned to the folks at Disney to help redesign the ride. Thank heavens for Space Mountain!
These same minions are trying to design the new rockets, spacecraft, and lunar landers, yet can't satisfactorily solve the simple escape ride problem on their own. We're just hoping that Wile E. Coyote won't be called in next to solve ARES' multiplicity of problems.